polak



Sept. 22, 1931. I I J. POLAK Re. 18,202

CASTING MACHINE- Original Fil'ed Aug. 8. 1928 2 Sheets-Sheet 1 INVENTOR.' BY (I PO/a/i i fl/b A TTORNEYS.

Sept. 22, 1931. J PQLAK Re. 18,202

usm'ue MACHINE Original Filed Aug. 8. 192 8 2 Sheets-sheaf. 2

s s V INVENTOR.

Arromy Reissued Sept. 22, 1931 Re. I 18,202 v PATENT. orrlcs J'OSEF POLAR, OF PRAGUE, CZECHOSLOVAKIA cas'rme MACHINE Original lie-1,717,254, dated June 11,1929, Serial No. 298,329, filed August 8, 1928, and in Czechoslovakia September 1, 1927. Application for reissue filed June 8, 1931'. Serial No. 542,989.

This invention relates to a casting machine in which the molten metal is forced out of a cylinder by means of a sliding piston directly into the moulds.

this, that the plunger is made removable. from the cylinder, for enabling the latter to be filled, while the piston forming the bottom of the cylinder, on which the molten metal poured into the cylinder rests, on the one hand normally closes theconnecting passages between the interior of the cylinder and the moulds lying directly next to it and on the other hand, when exerting the casting pressure, rests on the bottom of the cylinder 15, and finally after the casting operation has been completed and the plunger has been withdrawn, ejects the remaining metal out of the cylinder, at the same time separating the runner in the mould from the rest of the metal.

Owing to this arrangement it is possible to cast with metals having a high melting point since thebottom piston which rests on the bottom of the cylinder enables a great pres- 28 sure to be exerted on the "metal resting on it; Animportant feature is that with this machine from the time of pouring the metal into the cylinder up to the introduction of the plunger into the latter and the displace- '30 ment of the plunger the molten metal partly solidifies in its outer layer. Owing to this when the castin pressure is applied, the partly solidified l yer formed around the liquid metal core must first be broken through in order to allow the viscous metal to enter the casting passages.

In the-accompanying drawings two con-' structional examples of the moulding machine are shown, Fig. 1 being a vertical section through one constructional form, Fig.

2a verticalsection through the second constructional form and Figs. 3 and 4 showing the plunger and the bottom piston in differentoperative positions in the cylinder of the 5 second constructional form. In the various figli'res similar constructional parts bear similar reference letters.

1th,e moulds d, e are adapted to be brought )0 up from the side to the cylinder a which is The invention consists in,

open at the top, for introducing the projections on the moulds, which are provided with the passages Z, into corresponding holes. m in the wallof the cylinder, in which they fit tightly. In the cylinder (1 a piston c is supported by a spring f such that it normally shuts off the hole m in the cylinder wall or the passage l from the interior of the cylinder. The piston rodof the piston c is pivotally attached to a pivoted lever 9 so that the piston 0 can either be lowered to the bottom of the cylinder or by moving the lever 9 upwards can eject the remainder of the metal out of the cylinder a afterthe casting operation is completed, at the same time separating the runner which has solidified in the passage Z. from the metal remaining in the cylinder.

The plunger 5 is fixed to the transverse head piece 12 which is guided by rods n. The

latter are connected by a transverse head piece 2' to the rod of the piston j to which-motion is' imparted in the cylinder is by a controlled driving medium.

The machine operates in the following manner:

After the moulds have been brought up against the cylinder 0; (see Fig. 1 to the left) the cylinder is filled with the requisiteamount of molten metal, the supported piston 0 closing the inner opening of the passages Z. On the piston being moved downwards in the cylinder lolly means of the controlled drivin medium, the lunger b will directly and t e pistonc indirectly follow this motion, until the piston c rests -on the bottomof the cylinder a. During this partof the operation and during the subsequent downward motion of'theplunger b a thin outer layer of the molten metal partially solidifies, so that during-the subsequent application of pressure by the plunger '12 such a pressure is exerted on the metal that the solidified outer la er is broken through and themetal surrounded by it enters the'passage land the mouldsd, e. The piston j is thereupon moved in the opposite direction for the In the constructional form shown in Fig.

purpose of raising the plunger b out? of the cylinder a, and the piston .0 which moves upwards in the same direction through the ner opening the passage 1, at the same time separating the runner which solidifies in the passage-Z from the metal remaining in the rcylinder, after which, by actuating the lever the remainin metal is completely ejected from the cylinfer V p I The constructional form shown in Fi s. 2, 3 and 4- differs from that described a ove in this, that the piston used for ejecting the remaining metal out of the cylinder already rests on the bottom of the cylinder, when the molten metal is being introduced into the latter, and remains in that position during the whole of the casting operation; By being turned about its axis the bottom piston establishes the connection between the casting passages which are otherwise shut off by it and the interior of the cylinder. This has the advanta e that, during the casting operation, only t e plunger has to be axially displaced in the cylinder but need no longer be guided with a sliding fitas it only comes in contact with the metal when a thin layer of the surface of the latter has become relatively solid.

In contradistinction to the constructional form shown in Fi 1 the piston 0 rests on the bottom of the cy inder a while the latter is being filled and during the casting operation. The piston 0 is, provided at certain places with grooves 0. rising from the edge of the piston towards the center.

' The rod 8 of the piston 0 extends through the transverse head piece i and is provided with an arm 1" b action of the s ring 7, again shuts off the in- The plunger 6 during its further motion will produce a pressure in the column of metal so that finally the liquid metal core will break from the solidified thin outer layer and be forced into the moulds (1, e.

After the casting operation has been completed the plunger 6 moves back again in'the manner described above. At the-same time the transverse head iece. i by means of the driving member 0, w ich rests across it, carries the piston 0 along with it, whereby the runner in the passageZ is separated from the metal remaining 111 the cylinder and'the latter is ejected from the cyllnder. The rod 8 of the piston 0 is thereupon turned in such a manner that its driving member 0 can pass through the slot t in the transverse head piece 2' under the action of gravity on the piston and the rod, whereby the piston c is a ain brought into a position on the bottom of the cylinder in which the casting passages Z are means of which it'can be turned. The ro s is further provided witha driving member 0 which, when in a certain position, can pass through the slot 25 in the transverse head piece 11 or, on-the rod .9 being turned by means of the arm 1', rests across the .tween the grooves 0'.

slot t in the transverse head piece i so that the transverse head piece in its upward motion carries the rod 8 with it.

Thismachine' operates in the following manner:

After the moulds d, ewhave been brought up against the cylinder (1 thelatter is filled with molten metal while the plunger 6 is in thefposition shown inFig. 2. The piston c closes the casting passages lb means of the cylindrical parts of, its peripli .The plunger (2 is thereupon moved downwards in the manner alread described,.dur-

.ing which motion the slot't ln the transverse head piece '5 is pushed over the driving member 0 on the rod s. The rod 8 and with it the piston c is thereupon turned at the suitable moment by means of the lever r or by means of any suitable mechanism in such a manner that the grooves c in the piston a will lie opposite the casting passages l. The driving member oon the rod 8 will then lie across the slot t in the transverse head piece i.

cry lying beagain shutoff from the interior of the cylinder.

During the pressing operation, therefore, the piston 0 only' makes a small rotary motion.

As will be seen from the drawings, the

plunger b may have its end surface formed so as to correspond to the piston 0. The-end surface of the plunger b is therefore provided with the ribs 5 inclined downwards to wards the middle. When the piston c is in -'the castingposition (Fig. 3), channels are formed by the opposing end surfaces of the plunger 5 and the piston c, which directly face the casting passages]. This arran ement allows the metal to pass more rapidly from the cylinder to the moulds.

. What I claim is:

1 A casting machinecomprising in combination a cylinder capable of being filled with molten metal, lateral o enings in the walls of the cylinder, a plurallty of moulds capable of being moved so as to bring their gates up against the said lateral openings, a plunger capable of sliding axially in the cylinder for producing the casting pressure and of being withdrawn from the cylinder while the molten metal is being introduced into the latter and a piston 'capableof sliding in the cylin-' der, of shutting off the openings in the cylinder walls during the introductionof the mol- I ten metal and of ejecting the superfluous metal remainin 1n the cylinder after the completion of t e casting operation, as and for the purpose set forth.

' 2. A casting machine comprising in combilgo nation a cylinder capable of being filled with molten metal, lateralopenings in the walls of the cylinder, a plurality of moulds capable of bemg moved so as to bring their gates up against the said lateral openings, a plunger capable of slidingaxially in the cylinder for producing the casting means-forwithdrawing t e plunger from the plressure, controlled I cylinder for enabling the latter to be'filled with the molten metal and a piston capable of sliding in the cylinder, of shutting oil the openings in the cylinder walls during the introduction of the molten metal and of ejecting the superfluous metal remaining in the cylinder after the completion of the casting operation, as andfor the purpose set forth.

3. A casting machine comprising in combination a cylinder capable of being filled with molten metal, lateral openings in the walls of the cylinder, a plurality of moulds capable of being moved so as to bring their gates up against the said lateral openings, a plunger capable of sliding axially 1n the cylinder for producing the casting pressure and of being withdrawn from the cylinder while the molten metal is being introduced into the latter, a piston capable of sliding in the cylinder and of e'ecting the su ,erfluous metal remaining in t e cylinder a ter the casting operation and means for moving the plston in front of the gates of the moulds while the molten metal is being introduced into the cylinder and for allowing it to rest on the bottom of the cylinder during the application of pressure by the plunger, as and for the purpose set forth. 4. A casting machine compris ng in combination a cylinder capable of being filled with molten metal, lateral openings in the walls of the cylinder, a plurality of moulds capable of being moved so as to bringthelr gates up against the said lateral-openmgs, a' plunger capable of slidlng axially 1n the cylinder for producing the casting pressure and of being withdrawn from the cylinder while the molten metal is being introduced into ,the latter, a piston capable of sliding in the'cyl- ,inder for ejecting the superfluous metal remaining i'nthe cylinder afterthe casting operation and means for rotating the plston about its axis as it rests on the bottom of the cylinder for closing thegates ofthe moulds during the filling o metal and for opening the gates during the casting operation, as and for the purpose set forth.

' 5. A casting machine comprising in combination a cylinder capable of being filled withimolten'metal, lateral opemngsm the walls of the cylinder, a plurality of moulds capable of being moved so as to brlng their and of being withdrawn from the cylinder while the molten metal is being introduced I gates up against the said lateral openings, a

plunger capable of sliding axially 1n the cylinder for producing the casting pressure into the latter, a piston capable of sliding in the cylinder for ejecting the superfluous metal remaining in thec'ylinder after the casting operation, means for rotating the piston about its axis as it rests on thebottom of the cylinder, depressions on' the upperface of the piston, extending-from the cylinthe cylinder with'molten drical edge upwards and inwards towards the middle thereof and capable of being blocking the said gates while the cylinder is being filled with the molten metal,v as and for the purpose set forth. v

6. A casting'machine comprising in combination a cylinder capable of being filled with molten metal, lateral openings in the walls ofthe cylinder, a plurality ofmoulds capable of being moved so as to bring their gates up against the said lateral openings, a .plunger capable of sliding axially in the cylinder for producing the, casting pressure and of being withdrawn from the cylinder while the molten metal is being introduced into the latter, a guided cross head piece for supporting the plunger, a slot in the said cross head piece, a piston capable ofsliding in the cylinder, for ejecting the superfluous metal remaining in the cylinder after the casting operation, a piston rod for supporting the said piston extending through the said slot, a driving member on thesaid piston rod, means for'turning the piston rod for causing the driving member to pass through the said slot during the motion of the cross headpiece and plunger before the casting operation and for causing the driving member to engage across the slot after the casting operation,- whereby during the upward motion of the cross head piece andplunger for opening the cylinder the piston is caused to take part in the said motion, as

and for the purpose set forth.

7., casting machine comprising in combination a cylinder capable of being filled with molten metal, lateral openings in the walls of the cylinder, a plurality of moulds capable'of belng moved so'as to bring their gates up against the said lateralopenings, a plunger capable'of sliding axially in the cylinder. for producing the casting pressure and of being withdrawn from the. cylinder while the molten metal is being introduced nto the latter, a piston capable of sliding 1n the cylinder for ejecting the superfluous metal remaining in the cylinder after the casting operation, means for rotating the.

piston about its axis as it rests-on the bottom of the cylinder for closing the gates of the moulds during the filling of the cylinder with molten metal and for opening the gates during the casting operation and raised edges on the face of the plunger, .falling away towards the center thereof, capable of forming with the face of the piston channels directed towards the gates of the moulds for the passage of the molten metal from the cylinder into the moulds, as and forthe purpose set forth.

bination a cylinder capable of being filled with molten metal, said cylinder having a lateral opening in the wall thereof, a mould capable ofbeing moved so as to bring its gate up against the said lateralopening, a

plunger capable of sliding axially in the cylinder for producing the casting pressure and of being withdrawn fromthe cylinder while the molten metal is being introduced into the latter and a piston capable of sliding in the cylinder, of shutting off the opening in the cylinder wall during the introduction of the molten metal and of ejecting the superfluous metal remaining in the cylinder after the completion of the casting operation, as and for the purpose set forth.

9. A casting machine comprising in combination a cylinder capable of being filled with molten metal, said cylinder, having'a lateral opening in the wall thereof, a mould capable ofbeing moved so asto bring its gate up against the said lateral opening, a plunger capableof sliding axially in the cylinder for producing the casting pressure and of being withdrawn from the cylinder while the molten metal is being introduced into the latter, a piston capable of sliding in the cylinder for ejecting the superfluous metal remaining in the cylinder after the casting operation, means for rotating the piston about its axisas it rests on the bottom of the .03 1- inder, a depression on the upper face of the,

piston extending from. the cylindrical edge upwards and inwards towards the middle thereof and capable of being brought by the rotation of the piston inv alignment with'the gate of themould for establishing communication with the interior of thecylinder dur= ing the casting operation and out of align- I ment with the gate for blocking the said gate while the cylinder is being, filled with the p molten metal, as and for the purpose set forth. 1

10. A casting machine comprising in combination a cylinder capable of being filled with molten metal, said cylinder having a lateral opening in the Wall thereof, a mould capable of 'being moved so as to bring its .gate up against the said lateral opening, a zplungercapable of sliding axially in the .cyl-.

inder for producing the casting pressure and of being withdrawn from the cylinder while the molten metal is being introduced into the latter, a guided cross head piece for supporting the plunger, a slot in the said cross head piece, a piston capable of sliding in the cylin- 'der, for ejecting the superfluous metal remaining in the cylinder after the casting operation, a piston rod for supporting the said piston extending through the said slot, a driving member on the said piston rod, means for turnin the piston rod for causing the driving memb'erto pass through the said slot during the motion of the cross head piece and plunger before the casting operation and for causing the driving member to engage acrosstheslotafter the casting operation, whereby during the upward motion of the cross head piece and plunger for opening the cylinder the piston is caused to take part in thesaid motion, as and remaining in the cylinder after the casting 7 operation, means for 'rotatin the piston about its axis as it rests on the ottom of the cylinder for closing the gate of the mould during thefilling of the cylinder with molten metal and for opening the gate during the casting operation and a raised edge on the face of the plunger, falling away towards the center thereof, capable of forming with the face of the piston a channel directed towards the gate of the mould for the passage of the molten metal from 'thecylinde'r into the mould, as anda for the purpose set forth.

J OSEF POLAKQ v p v 

